Biology subjects

Devkota, R.

Publications and source records attributed to Devkota, R..

3 recordsLinked to original sources

bioRxiv2021

Sphingosine 1-Phosphate Mediates Adiponectin Receptor Signaling Essential For Lipid Homeostasis And Embryogenesis

Cells and organisms require proper membrane composition to function and develop. Phospholipids are the major component of membranes and are primarily acquired through the diet. Given great variability in diet composition, cells must be able to deploy mechanisms that correct deviations from optimal membrane composition and properties. Here, using lipidomics and unbiased proteomics, we found that the embryonic lethality in mice lacking the fluidity regulators Adiponectin Receptors 1 and 2 (AdipoR1/2) is associated with aberrant high saturation of the membrane phospholipids. Using mouse embryonic fibroblasts (MEFs) derived from AdipoR1/2-KO embryos, human cell lines and the model organism C. elegans we found that, mechanistically, AdipoR1/2-derived sphingosine 1-phosphate (S1P) signals in parallel through S1PR3-SREBP1 and PPAR{gamma} to sustain the expression of the fatty acid desaturase SCD and maintain membrane properties. Thus, our work identifies an evolutionary conserved pathway by which cells and organism achieve membrane homeostasis and adapt to a variable environment.

cell biology↗

bioRxiv2020

Genome wide identification of QTL associated with yield and yield components in two popular wheat cultivars TAM 111 and TAM 112

Two drought-tolerant wheat cultivars, TAM 111 and TAM 112, have been widely grown in the Southern Great Plains of the U.S. and used as parents in many wheat breeding programs worldwide. This study aimed to reveal genetic control of yield and yield components in the two cultivars under both dryland and irrigated conditions. A mapping population containing 124 F5:7 recombinant inbred lines (RILs) was developed from the cross of TAM 112/TAM 111. A set of 5,948 SNPs from the wheat 90K iSelect array and double digest restriction-site associated DNA sequencing was used to construct high-density genetic maps. Data for yield and yield components were obtained from 11 environments. QTL analyses were performed based on 11 individual environments, across all environments, within and across mega-environments. Thirty-six unique consistent QTL regions were distributed on 13 chromosomes including 1A, 1B, 1D, 2A, 2D, 3D, 4B, 4D, 6A, 6B, 6D, 7B, and 7D. Ten unique QTL with pleiotropic effects were identified on four chromosomes and eight were in common with the consistent QTL. These QTL increased dry biomass grain yield by 16.3 g m-2, plot yield by 28.1 g m-2, kernels spike-1 by 0.7, spikes m-2 by 14.8, thousand kernel weight by 0.9 g with favorable alleles from either parent. TAM 112 alleles mainly increased spikes m-2 and thousand kernel weight while TMA 111 alleles increased kernels spike-1, harvest index and grain yield. The saturated genetic map and markers linked to significant QTL from this study will be very useful in developing high throughput genotyping markers for tracking the desirable haplotypes of these important yield-related traits in popular parental cultivars.

genetics↗

bioRxiv2020

AdipoR2 is Essential for Membrane Lipid Homeostasis in Response to Dietary Saturated Fats

Membrane lipid composition influences vital processes in all types of cells. The mechanisms by which cells maintain membrane lipid homeostasis while obtaining most of their constituent fatty acids from a varied diet remain largely unknown. In an attempt to discover such mechanisms, we performed an unbiased forward genetic screen in Caenorhabditis elegans and conclude that the adiponectin receptor 2 (AdipoR2) pathway is essential to prevent saturated fat-mediated cellular toxicity. Transcriptomics, lipidomics and membrane property analyses in human HEK293 cells and primary human endothelial cells further support our conclusion that the essential function of AdipoR2 is to respond to membrane rigidification by promoting fatty acid desaturation. Our results demonstrate that AdipoR2-dependent regulation of membrane homeostasis is a fundamental mechanism conserved from nematodes to mammals that prevents saturated fat-mediated lipotoxicity. ONE SENTENCE SUMMARYThe AdipoR2 protein insures membrane homeostasis in response to dietary saturated fatty acids that promote membrane rigidification.

cell biology↗